Dividers.



No. 63l,987. PatentedAug. 29, |899.`

F. H. DE TRAY DIVHJERS:A

(Application filed Max'. 12, 1898,)

2 Sheets-Sheet i,

(No Model.)

The Nonms versus co.. PHm'cLLrrwQ, wAsHmmoN, D. c.

No. 631,987. y Patented Aug. 29, |899.

F. H. DE TRAY.

DIVIDERS.

(Application led Mar. 12, 1898.)

2 Sheets-Sheet 2.

(No Model.)

g fa imi muliliili claims.

UNITED STATES PATENT OEEICE.`

FREDERICK H. DE TRA-Y, OF QINOY, ILLINOIS, ASSIGNOR OF ONE-FOURTH TO EUGENE B. POTTER AND ADAM ROHRBOUGH, OF SAME PLACE.

'sEcIrreAcrroN forming part of Letters Patent'No. 631,987, dated August 29,1899.

Application filed March 12, 1898.

To all whom it may concern.-

Be it known that I, FREDERICK H. DE TRAY, av citizen of the United States, residing at Quincy, in the county of Adams and State of Illinois, have invented new and useful-Dividers, of which the following is a specification.

My invention lrelates to dividers designed for use by architects, draftsmen, surveyors, civil engineers, professors of mathematics, and others in the demonstration of mathematical and analogous problems, the dividers being provided with suitable scales, geometrical and otherwise, and the members thereof being so constructed and arranged as to adapt them for relative adjustment, such as to enable the operator to avoid the loss of time ordinarily consumed in calculation and at the same time attain a desirable accuracy in measurement and proportion.

The object of my invention is to provide a simple and compact construction and arrangement of parts, including oppositely-extending long and short arms, so mounted as to enable the points of the short arms to lay off decimal parts of a unit of measurement of which the points of the long arms indicate the unit, or` a multiple thereof, the relative adjustments of the long and short arms being such as to provide for varying with accuracy the relation between the measurements laid oif, respectively, by the points of the long and short4 arms.

Further objects and advantages of this invention will appear in the following description and the novel features thereof will be` particularly pointed out in the appended In the drawings, Figure l'is a View of dividers constructed in accordance with my invention, showing the members closed or in their normal relative positions. Fig. 2 is a view showing the members spread for operation. Fig. 3 is a longitudinal sectional view ou the plane indicated by the line 3 3 of Fig.1. Fig. 4 is a detail view in perspective of the rack-bar and adjusting connections. Fig. 5 is a similar view of the latch. Fig. 6 is a detail sectional View of the interlocking members of the holding devices on the line 6 6 of- Fig. 1. Fig. 7 is a detail view in perspective Serial No. 6733618. (No model.)

of one of the short arms. Fig. 8 is a face view of the quadrant-plates to show the cooperating scales thereon. Fig. 9 is a perspective view of a gage adapted for accu- 55 rately setting the long arms with relation to the pivotal point of connection of the members.

Similar numerals of reference indicate corresponding parts in all the figures of the drawlugs.

The members of the dividers embodying my invention consist of pivotally-connected quadrant-plates 1 and 2, each of which carries a long arm 3 and a short arm 4, the pivot 5, by which the quadrant-plates are connected, consisting of a bolt extending transversely through the plates at their reduced ends and being arranged concentrically with the segmental faces 6, which consist of inturned iianges at the outer edges of the plates. Carried by and preferably formed integral with the plates are yokes 7, provided at their centers with sockets 8, in which are fitted the reduced inner extremities of the removable long arms 3, said arms having cross-sectionally angular reduced portions 9, fitting in correspondiugly-constructed portions of the sockets, and also with extensions 10, fitting in reduced extensions of the sockets and engaged by thumb-screws 11 or 'equivalent fastening devices. The reduced bearing portions 9 of the arms allow longitudinal extension of the latter to secure the desired adjustment in connection with a gage (illustrated in Fig. 9) and consisting of a bar 12, suitably graduated to indicate linear measurements, having fixed and adjustable heads 13 and 14, of which the f latter is adapted to traverse the scale and is provided with a set screw 15 to secure it at the desired adjustment and a fixed point 16, arranged at the initial point of the scale for alinement with the pivotal point of connection of the divider members. By disposing the extreinityof the pivot upon the point 16, the adj ust-able head 14 having been arranged previously at the desired adj ustment,the contact of the extremities ofthe long arms withthe plates of the head 14 will indicate thev proper position of the long arms, whereas any interval between the points of the arinsand the face of the head 14 will indicate the ne- IOO ' plates the latter are also preferably provided with side flanges 17 to serve as means for protecting the parts of the instrument which are located between the planes of the plates and which include the extensible short arms 4. These short arms are longitudinally slotted, as shown at 18, and the pivot-bolt 5 extends through the slots of the short arms at their point of registration irrespective of the relative positions of the quadrant-plates. The inner ends of the short arms are provided with guiding projections or bosses 19, fitting' in radial slots 2O in the quadrant-plates, and fitted upon said projections or bosses beyond the faces of the quadrant-plates are doublearmed pointers 21, which traverse parallel scales 22-upon opposite sides of the slot, one of said scales preferably being in accordance with the metric system of notation. yThe pointers 21, which are provided with angular openings to receive the outer extremities of the correspondingly-constructed projections or bosses 9, are held in place by thumb-.nuts 23, threaded upon reduced stems, and this relative arrangement of parts insures the accurate guiding of the inner ends of the short arms of the dividers in' their radial adjustment to secure the desired extension of the points. The short arms at their points contiguous to the pivot 5 operate in contact and respectively through guide-openings formed by the cut-away portions of the flange 17 of the quadrant-plates. The construction of points which are preferably employed in connection with the short arms includes needles 24, fitting in contractible sockets 25 of tapered or conical exterior construction, and the latter in turn fit in seats 26, formed in the ends of the arms 4, said seats being inclined to brin g the extremities of the needles approximately into contact or in the planes of the inner or contiguous surfaces of the arms. The sockets 25 are also of longitudinally split construction, whereby after the insertion of a needle the introduction of the socket into its seat causes the contraction of the socket, and hence the secure locking of the needle in place at the desired adjust` ment. Also the expansion or the resistance of the socket to contraction serves to firmly retain the socket in the seat 2G.

The means disclosed in the drawings for adjusting or setting the members of the dividers and holding them during use at the desired adjustment include a segmental rack or setting-bar 27, tted in a cross-sectionallydovetailed guide 2S within the quadrant-plate or segmental-faced member 1 of the instrument for linear adjustment, said guide preferably consisting of a cross-sectionally-dovev ries of spaced notches or seats 29 for engagetailed channel cut in the inner surface of th plate. This rack-bar is provided in its periphery, preferably its outer edge, with a sement by a spur or tooth 30 on a yielding latch 3l, which is mounted, preferably, upon the face of the said segmental-faced member 1. In the construction illustrated this latch consists of a plate-spring secured at one end, as by a screw 32, to the member and terminatin gin the above-described spur or tooth,which extends inwardly through a suitable perforation 33 in the flange 6. Contiguous to its free end, however, this latch is provided with an ear 34, which in the construct-ion illustrated is arranged parallel and in contact with the side surface of the plate 1 and is fitted with a thumb-hold 35, having a stop-pin 36, which extends into a slot 37, formed in the plate, whereby the swinging movement of the latch at its free end is limited, but at the same time is sufcient to allow the disengagement of the spur or tooth 30 from the notches or seats of the rack-bar when outward pressure is manually applied to the thu mb-hold 35. By means of the rack-bar and latch a coarse or approximate adjustment of the members of the dividers may be attained without loss of time; but in order that an accurate or nice adjustment thereof may be accomplished I employ feeding devices in connection with the rack-bar, and in the construction illustrated these feeding devices include a feed-screw 3S, swiveled ina suitable bracket 39 in the member '2 and having a terminally-exposed .thumb nut or hold 40 and a feed n ut or block 41, into which said feed-screw is threaded and which in turn is swiveled upon the rackbar by means of a screw 42 or its equivalent. The feed-nut is provided concentric with its pivot screw with a trunnion 43, which ex- .tends laterally through a slot 44 in a guide plate or keeper 46, as shown in Fig. 6. Hence after the course or approximate adjustment of the members of the dividers by the engagement of the latch with one of the notches of the vrack-bar, thus locking in a iixed relative position the member 1 and said rack-bar, the feed-screw may be operated by turning the thumb nut or hold 40 to vary the position of the rack-bar in its guide, and hence of the member 1 with relation to the member 2.

I have also foundit desirable in a device yof this class to provide means for insuring the proper relative swinging movements of the segmental-faced members 1 and 2, and in order to accomplish this I provide au interlocking joint between said members con-r tiguous to their segmental faces, such interlocking connection in the construction illustrated including an inturned lip or tongue 47 on one of the members fitting in a groove o'r channel 47 t in the other member, this interlocking connection being continuous throughout the lengths of the segmental faces. Obviously as the segmental faces extend for a considerable distance upon each side of the lines of the divider-arms the members of the interlocking joint remain in engagement in all adjustments of the divider members, and

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thus insure an accurate relative arrangement of the extremities of the long arms and relieve the pivot-pin 5 of transverse strain. The extent of angular adjustment of the di-Y vider members is indicated by the coperative scales formed on the faces 6.

It will be understood that While in the description and drawings I have set forth the preferred embodiment of my invention, including suitable means of adjustment for securing that accuracyin relative arrangement which is desirable in instruments designed for use in connection with mathematical calculations, various changes in the form, proportion, and the minor details of construction may be resorted to without departing from the spirit or sacrificing any of the advantages of this invention.

Having described my invention, what I claim is 1. Dividers having pivotally connected members provided, concentric with their pivot, with a segmental interlocking joint, and carrying long and short arms, substantially as specified.

2. Dividers having pivotally connected members provided, concentric with their pivot, with a segmental interlocking connection consisting of a lip or tongue on one of the members permanently engaging a channel in the other member, said members carrying long and short arms, substantially as specified.

3. Dividers having pivotally connected members carrying long and short arms, and provided, concentric with their pivot, with segmental interlocking guiding devices extending in opposite directions from the lines, of the arms, and parallel with the planes of swinging movement thereof substantially as specified.

4. Dividers havin g pivotally-connected segmental-faced plates or members carryinglong arms, extensible short arms mounted to slide respectivelyupon the plates or members, and provided with projections operating in radial slots therein, pointers adjustably mountedv upon said projections to traverse scales parallel with the slots in the plates or members, and common locking devices for holding the pointers in place and securing the short arms in their adjusted positions, substantially as specified. t

5. Dividers having pivotally-connected segmental-faced plates or members provided with radial slots and carrying long arms, extensible short arms mounted to slide upon the plates or members and having angular projections extending through said radial slots, pointers having openings fitted upon said projections to traverse scales on the exterior surfaces of the plates or members parallel with the slots therein, and thumb-screws threaded upon extensions of said projections to clamp the pointers upon the surfaces of the plates or members and secure the short arms in their adjusted positions, substantially as specified.

6. Dividers having pivotallyLconnected arm= carrying plates, a transversely-fixed, longiL tudinally adjustable setting bar housed within and mounted upon one of the plates, a latch mounted upon the other plate for movement in a direction transverse to the seta ting-bar, and having means for engaging the setting-bar at spaced points, and adjusting devices, including a feed nut, pivotally mounted upon the setting-bar, and a feed screw mounted upon the first-named plate and engaging said nut, for varying the longitudinal position of the setting-bar with relation to said plate, substantially as specified.

7. Dividers having pivotally=connected armcarrying plates, and setting devices including a setting-bar mounted upon one of the plates for sliding movement concentric with the pivot of the plates, a slotted guiding-keeper, a swiveled feed-screw, and a feed-nut pivotally mounted Vupon the setting-bar, engaged by said feed-screw, and having a trunnion mounted in the slot of the keeper, and a latch carried by the other plate for engagement with the seats of the setting-bar, substantially as specified.

8. Dividers having pivotallyconnected plates or members, and means for securing the same at the desired angular adjustment, yokes carried respectively by the plates or members and provided with cross-sectionally angular sockets alined with the pivotal point of the plates or members, short arms carried by the plates or members, long arms fitted respectively to slide in said sockets, and securing devices for fastening the long arms at the desired adjustment, substantially as specied.

In testimony that I claim the foregoing as my own I have hereto affixed my signature in the presence of two Witnesses.

l FREDERICK H. DE TRAY.

Vitnesses:

THOMAS RD. SLEDDING, ADAM ROHRBOUGH.

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